To be exact, they’ve calculated that 322,083 PS4 units were sold from February 22nd until February 23rd. In comparison, the PS3 sold only 88,443 units in its first two days when it was released in Japan back in late 2006.
The fact that the PS4 sold three times as much as the PS3 at launch is very impressive. On a worldwide basis, the console has sold 5.3 million units so far. Sony is likely to update this figure very soon with the way things are going in Japan.